In a test performed by applying predetermined stress such as voltage to a self-heating electronic component at a predetermined test temperature, the temperature of the electronic component becomes higher than the test temperature due to self-heating of the electronic component. For this reason, a cooling mechanism has been conventionally used to maintain the temperature of the electronic component in a certain range.
For example, Japanese Patent Application Laid-Open No. 2009-250810 discloses a temperature control device as a temperature control device for the above purpose. The disclosed temperature control device includes: a cooling device including a flow path through which coolant flows and a heat-absorbing unit and a heat-releasing unit provided halfway of the flow path, and configured to exchange heat of the electronic component absorbed by the heat-absorbing unit with the coolant in the heat-releasing unit to cool the electronic component by allowing an electronic component to directly or indirectly contact the heat-absorbing unit; a heating device configured to heat the electronic component; and a control unit configured to control the temperature of the electronic component by controlling operation of the heating device. The heat-releasing unit of the cooling device includes a heat-releasing member made of a foam metal material.
The above-configured temperature control device according to Japanese Patent Application Laid-Open No. 2009-250810 has an excellent response in feedback control of the temperature of an electronic component with a large self-heating amount, and allows a characteristic examination to be performed on the electronic component while accurately maintaining the temperature of the electronic component at a predetermined temperature.
However in the case of Japanese Patent Application Laid-Open No. 2009-250810, a member (heat-transfer block 9 (refer to FIG. 1 in Japanese Patent Application Laid-Open No. 2009-250810)) including a temperature sensor (a first temperature sensor 11 (refer to FIG. 1 in Japanese Patent Application Laid-Open No. 2009-250810)) has a large heat capacity, which causes underestimation of the temperature of the electronic component due to diffusion of heat transferred from the electronic component, and thus the temperature of a self-heating electronic component cannot be accurately detected.
In particular, in a test performed by applying voltage to an electronic component having a negative resistance temperature characteristic, a phenomenon called thermal runaway may occur. In the thermal runaway, self-heating due to energization increases the temperature of the electronic component, the temperature increase reduces resistance and increases current accordingly, and then the current increase increases self-heating. Thus, in such an electronic component, feedback control cannot be performed fast enough to handle self-heating, causing the thermal runaway.
Japanese Patent Application Laid-Open No. 2008-275512 discloses an aging device configured to cool a self-heating sample body to perform temperature adjustment by bringing the sample body into contact with a cooling plate, heat of which is exchanged through a coolant supplied from a coolant supply unit. The aging device includes a temperature detection unit configured to detect the temperature of the sample body, and a coolant flow rate adjuster configured to adjust the flow rate of the coolant supplied by the coolant supply unit based on a result of the temperature detection of the sample body by the temperature detection unit.
It is disclosed that the aging device can reduce change in the temperature of a self-heating sample body by following the change.
However, in the aging device, too, a temperature sensor is directly attached to the sample body. When a large number of electronic components need to be frequently replaced to measure temperature, work needs to be done to attach a temperature sensor at each exchange of electronic components as measurement targets, which is inefficient. When a temperature sensor is attached to a water-cooling plate, the temperature of the sample body is not directly measured, and thus the temperature of a self-heating electronic component cannot be accurately detected due to underestimation of the temperature of the electronic component, which is a problem the same as that of Japanese Patent Application Laid-Open No. 2009-250810.